Porter's stemming algorithm for 'generic' english
use Lingua::Stem::EnBroken; my $stems = Lingua::Stem::EnBroken::stem({ -words => $word_list_reference, -locale => 'en', -exceptions => $exceptions_hash, });
This routine MIS-applies the Porter Stemming Algorithm to its parameters, returning the stemmed words. It is an intentionally broken version of Lingua::Stem::En for people needing backwards compatibility with Lingua::Stem 0.30 and Lingua::Stem 0.40. Do not use it if you aren't one of those people.
It is derived from the C program \*(L"stemmer.c\*(R" as found in freewais and elsewhere, which contains these notes:
Purpose: Implementation of the Porter stemming algorithm documented in: Porter, M.F., "An Algorithm For Suffix Stripping," Program 14 (3), July 1980, pp. 130-137. Provenance: Written by B. Frakes and C. Cox, 1986.
I have re-interpreted areas that use Frakes and Cox's \*(L"WordSize\*(R" function. My version may misbehave on short words starting with \*(L"y\*(R", but I can't think of any examples.
The step numbers correspond to Frakes and Cox, and are probably in Porter's article (which I've not seen). Porter's algorithm still has rough spots (e.g current/currency, -ings words), which I've not attempted to cure, although I have added support for the British -ise suffix.
2003.09.28 - Documentation fix
2000.09.14 - Forked from the Lingua::Stem::En.pm module to provide a backward compatibly broken version for people needing consistent behavior with 0.30 and 0.40 more than accurate stemming.
Stems a list of passed words using the rules of \s-1US\s0 English. Returns an anonymous array reference to the stemmed words. Example: my $stemmed_words = Lingua::Stem::EnBroken::stem({ -words => \@words, -locale => 'en', -exceptions => \%exceptions, });
Sets the level of stem caching. '0' means 'no caching'. This is the default level. '1' means 'cache per run'. This caches stemming results during a single
call to 'stem'.
'2' means 'cache indefinitely'. This caches stemming results until
either the process exits or the 'clear_stem_cache' method is called.
Clears the cache of stemmed words
This code is almost entirely derived from the Porter 2.1 module written by Jim Richardson.
Lingua::Stem
Jim Richardson, University of Sydney [email protected] or http://www.maths.usyd.edu.au:8000/jimr.html
Integration in Lingua::Stem by Benjamin Franz, FreeRun Technologies, [email protected] or http://www.nihongo.org/snowhare/
Jim Richardson, University of Sydney Benjamin Franz, FreeRun Technologies
This code is freely available under the same terms as Perl.